Evolutionary Theory

Helping and altruism may also be approached through the framework of evolutionary theory. An evolutionary approach promotes the understanding of affect, cognition, motivation, and behavior as expressions of functional, adaptive processes that evolved through natural and sexual selection to solve problems in our ancestral environments. Evolutionary psychology is concerned with the conditions that existed in ancestral environments, the proximate mental mechanisms that evolved to deal with conditions in this environment, and the function of these evolved mechanisms in our current environments (Cosmides & Tooby, 1987; Crawford, 1998). The hereditary influences that were adaptive in our ancestral past are still expressed in the context of the natural and artificial environments of today. There is currently no grand unifying theory of social psychology, it is an amalgamation of many separate specialized areas of research. Framing knowledge about human cognition and behavior in terms of adaptive functions would lend coherence and commonality to the massive amount of social psychological data that has been collected in the past century. The evolutionary approach has a great potential to provide coherence to psychology and may also poise psychology for the eventual integration of the sciences.

In brief, evolution is understood as a change in genetic allele frequencies over time. Populations of living organisms have the potential to increase geometrically in size, although they remain relatively stable over time. The limitations on population size derive from the limitations on resources available, producing competition for these resources (Malthus, 1806). There is variation in the characteristics of individuals within a species, and some of this variation has a genetic component. Some of this variation affects the survival and reproduction of individuals (Darwin, 1859). Those characteristics with an inherent genetic component that enhance an individual's ability to survive and reproduce will be represented in increasing proportions with each generation, and may eventually spread though the population.

Selection refers to the process of change in gene frequencies over time due to differential survival and reproduction. Gene frequencies can also be changed through: genetic drift, a statistical bottleneck creating haphazard changes; genetic flow, the immigration and emigration of genes due to movements of individuals or gametes; and mutation, a change in genetic material often caused by errors in transcription and translation of genetic information. Mutation is critically important as the source of variation that selection works with, although it is a random, undirected process. Although mutation may occur in any of the dividing cells of the body, only mutations occurring in the germ cells are passed on to offspring. Recent evidence from genetic studies has indicated that most new alleles derive from mutations in sperm cells (Dickman, 1997). Because sperm producing cells divide much more often than egg cells, errors are more likely to occur in the male germ cells.

Of course, genes do not directly code for behaviors. Rather, “genes code for enzymes which, under the influence of the environment, lay down tracks of the brains and neuro-hormonal systems of individuals, thus affecting people’s minds and the choices they make about behavioral alternatives” (DeKay & Buss, 1992, p. 185). A gene for something merely indicates a tendency to do or be something. The context of a person’s social and physical environment is important in guiding if and how genetically based predispositions will be expressed as behaviors.

There are two main selection processes in evolution, natural selection and sexual selection. In the language of evolutionary theory, the probability that an individual will successfully reproduce by passing on her or his genes is called fitness. Natural selection determines evolutionary fitness with characteristics related to survival. Sexual selection is the process that determines who is able to successfully reproduce. Classical (Darwinian) fitness is based on an individual’s reproductive success in passing on traits to future generations through direct decedents.

An adaptation is an anatomical structure, a physiological process, a cognitive process, affective state, motivation, or a behavior pattern with an inherited basis that reliably emerges at the appropriate time(s) in an organism’s life, and helped to solve some problem in the ancestral environment. Initially, an adaptation begins as a mutation in a single individual (although it is theoretically possible to have multiple points of origin) and because it is necessary for or enhances reproductive success, it will pass on to more individuals in the next generation. Over time, an adaptation that continues to benefit fitness may spread to the entire breeding population. The environmental context may be critical to the development and/or expression of an adaptation. The qualities of pre-natal events and characteristics of the physical and social environment during development can lead to context-specific adaptations, such as the type of mating strategy exhibited (Buss, Haselton, Shackelford, Bleske, & Wakefield, 1998).

Inclusive Fitness Theory

A century of biological research supports Thomas Henry Huxley’s thesis, that the universe is hostile to life in general (Williams, 1993). This, however, does not require natural organisms to be "red in tooth and claw" in all cases. For example, by deferring reproduction up to seven years, juvenile Florida scrub jays increase their fitness because they help their parents raise additional broods of siblings (Crawford, 1998). According to classical fitness, members of a species that sacrifice their resources for the benefit of others will have fewer successful offspring, on average, and hence an inherent tendency towards this behavior would be selected against. Hamilton’s inclusive fitness theory (1964a) expanded the basis of reproductive success to include close relatives who become ancestors of offspring with similar genetic material. Despite Herbert Spencer’s catch phrase ``survival of the fittest,'' the ultimate criterion that determines if a genetic tendency for altruism spreads is whether it benefits the genes themselves, not whether it benefits the bearer of the genes (Hamilton, 1964b).

By assisting in a time of need, one would help his or her relative become an ancestor of offspring with similar genes. A genetically influenced tendency to help relatives is likely to spread across a population when the cost in reproductive fitness to the donor is less than the product of the fitness benefit to the recipient(s) and the proportion (designated “r”) of genes not common to the species that the donor and recipient(s) share. Identical twins have an r of 1.0; an individual’s siblings, parents, and offspring have an r of 0.5; aunts, uncles, nephews, nieces, grandparents and grandchildren have an r of .25; first cousins have an r of 0.125, etc.

For altruistic actions towards relatives, usually called kin selection, to be evolutionarily successful, potential altruists must be able to distinguish (consciously or subconsciously) between kin and non-kin (Schroeder, Dovidio & Piliavin, 1995). Kin recognition processes have been found to operate through visual (Porter, Cernoch, & Balogh, 1984), olfactory (Porter, Cernoch & Balogh, 1985), and social cues (Sherman, 1985). Helping behaviors based on kin recognition can be influenced by the social conventions of relationship status (Hawkes, 1983). There appears to be a critical developmental period for kin recognition, because unrelated children raised together do not typically develop romantic attractions to each other, reflecting an adaptation to promote outbreeding (Shepher, 1971; Wolf, 1970). In studies of rats, D’Amato and Pavone (1993) report that reunification and interaction with kin after a period of separation promotes the release of endogenous opiods at the neural level. The authors speculate that this is an indication of a reward mechanism for positive behaviors directed towards kin.

Kinship has played only a minor role in psychology, social psychological studies are typically based on the interactions of strangers. When close relationships are studied, they tend to be dating and marital relationships, with a secondary emphasis on friendships (Daly, Salmon & Wilson, 1997). Sociobiological studies have found that in situations of cooperative behavior exchange, brothers tolerate imbalances of reciprocity that would be considered exploitive and unacceptable in friendship not based on kinship (Hames, 1988). Even in a relatively non-kin based society such as our own, people turn to close relatives when in need, and are increasingly likely to do so the greater the imposition or demand (Hogan & Eggebeen, 1995).

Evolutionary Theory and the Study of Altruism

For example, altruist advocates cite the example of a mother rushing to help her injured child. To an evolutionary theorist, this is a blatantly obvious case of kin selection (Kenrick, 1991). Altruist advocates admit that evolutionary theorists have been useful in revealing how self-sacrificial behavior can be consistent with the theory of natural selection, however they are more concerned with the driving mental motivation of the helper (Batson, 1991). Research supporting the evolutionary perspective, on the other hand, does not necessarily need to identify the phenomenological experiences that influence the individual’s behavior, so long as this motivation leads to successful kin selection. From an evolutionary perspective, all common human motivational states would have, on average, served to increase the survival of our ancestor’s individual genes (Kenrick, 1991).

The two perspectives differ in the definition of who or what is assisted. For the altruist advocate, that entity is another individual. An evolutionary theorist would consider the genetic information in that individual (which may be similar to that of the donor’s) the ultimate benefactor. Consistent with evolutionary theory, felt oneness or empathy could arise as a consequence of attachment-related cues (kinship, friendship, familiarity) that signal the potential for relatively high genetic commonality. The psychological states provoked by these cues could increase the chances of the needy individuals receiving assistance, resulting in kin selecting behaviors and altruistic actions towards those who are likely to reciprocate. This would promote the spread of genes influencing the psychological capacity for oneness and empathy.

Also, genes that promote self-propagation may operate through actions that could be considered self-sacrificial from the perspective of the individual who carries them. It is possible that the psychological mechanism through which gene benefiting helping behaviors operate is the experience of empathy for another. It has been suggested that empathy manipulations might trigger a mechanism that causes the subject to think of the target as a fellow belonging to the same group (Kenrick, 1991).

Empirical Evidence for Inclusive Fitness Theory

The existence of kin selecting behaviors is well established for other members of the animal kingdom, but the mental aspects of kin selection are relatively unknown. Some claim that no clear evidence exists for the operation of inclusive fitness enhancing processes in humans (e.g., Batson, 1997). However, specific predictions for kin selection in humans have received empirical support. In a behavioral study, Essock-Vitale and McGuire (1985) found that (a) helping among friends was more likely to be reciprocated than helping among kin, (b) closer kin were more likely sources of help than were more distant kin, (c) helping was an increasing function of the recipient’s expected reproductive potential, (d) the larger the amount of help given, the more likely it was to come from kin, (e) childless individuals gave more help to their nieces and nephews, and (f) childless aunts received more help from nieces and nephews. Anthropological studies with quantifications of behavioral observations have consistently shown that cooperative and conflictual interactions are best predicted from genealogical relatedness, even when ideology and lip service say otherwise (Betzig & Turke, 1986). For example, kin selection based on intermarriages predicted which Binumarien communities in New Guinea were more likely to be at war (Hawkes, 1983).

A few social psychological studies on helping intentions have taken evolutionary considerations into account. Burnstein, Crandall and Kitayama (1997) provided a number of examples where respondents selectively chose to assist recipients in a fitness-enhancing manner. Burnstein et al. asked participants to indicate ''how closely related they felt'' to a large number of kindred (1997, p. 775). The differences in perceived relatedness among target characters of various genetic distances were significant; the largest difference was between close kin (parents and siblings, r =.5) vs. moderately close kin (aunts, uncles, grandparents, nieces and nephews, r = .25) and between distant kin (first cousins, great grandparents, r = .125) vs. non-kin (acquaintances, r near .00).

An evolved helping tendency may be most important in emergencies, rather than in the sort of helping behaviors under examination in typical laboratory studies (Kenrick, 1991). Everyday helping behaviors are not likely to have a great impact on the recipient’s survival or procreation. In a series of experiments, Burnstein et al. (1997) explored how the ''biological importance,'' or evolutionary fitness consequences, influenced target selection in life or death rescue scenarios and everyday helping behaviors. Intentions for everyday helping behaviors showed equal intervals of decline across targets in forced-choice assistance scenarios, yet intentions to assist for life-or-death scenarios mirrored the pattern found in perceived relatedness. Burnstein et al. (1997) also found that respondents were (a) more likely to help infants and the elderly in everyday situations but were more likely to save young targets (1, 10 and 18 years) than older targets (45 and 75 years) in life-or-death situations, (b) under famine conditions, more likely to save 10 and 18 year olds than those in the other age categories, (c) more likely to help kin with poor health in everyday situations, but kin with good health in life-or-death situations, and (d) more likely to help poor kin in everyday situations but wealthy kin in life-or-death situations. Cialdini et al. (1997) also reported that the effect of relationship closeness on helping intentions was stronger for higher need situations.

Two recent questionnaire studies have provided information on the psychological component of tendencies predicted by kin selection (Kruger, In Press a, In Press b). In the first study, participants read a number of scenarios where they were given two courses of action. Participants indicated the direction and strength of their preferences by circling a location on an unnumbered bipolar scale. Sixteen items contained scenarios where participants chose to bestow assistance affecting material wealth, social status, health, and pleasant experiences. Eight questionnaire forms were used to match each scenario with eight pairs of individuals. The pairs varied by gender and difference in relatedness: Sibling (brother/sister) vs. nibling (nephew/niece), nibling vs. cousin, sibling vs. friend, and nibling vs. friend (Kruger, In Press a). Items measured the tendency to favor the target character with the closer genetic relationship.

A 4 (type of scenario) x 4 (difference in relatedness) x 2 (gender in the scenario) ANOVA for mixed designs was used to analyze the data from the critical items. There were significant main effects for the type of scenario and the difference in relatedness. Significant interactions were found between gender of targets and type of scenario, and between the difference in relatedness and type of scenario. A simple effects analysis was conducted to clarify the effects of target gender and relationship comparison; results were evaluated using the HC-Holm procedure (Toothaker, 1993), to hold ERFW at .05. There was a significant difference in the intensity of kin selection based on the relationship comparisons for tangible and intangible resources, as well as for the pleasant/unpleasant situation scenarios. There was a significant difference in relatedness by target gender interaction for intangible resource scenarios, however, this did not occur for the other scenarios (Kruger, In Press a).

In life/health scenarios, the closer relation was favored for every condition except male siblings vs. nephews. For tangible resource scenarios, the closer relation was favored in all conditions except nieces vs. female cousins. Kin selection was evident in intangible resource scenarios, except for niece vs. female cousin and niece vs. female friend conditions. Intangible resource scenarios exhibited stronger kin selection for male targets than female targets. For the pleasant/unpleasant experience scenarios, kin selection was only apparent in the sibling vs. nibling and sibling vs. friend conditions. Linear contrasts indicated that comparisons with sibling targets exhibited more kin selection than those without sibling target for tangible resources, intangible resources, and pleasant/unpleasant experiences (Kruger, In Press a). These results supported the hypothesis that kin selecting processes could be revealed by standard social psychological methodology. In this study, only helping intentions were measured, so the qualities of the psychological mediator(s) of kin selecting tendencies were not revealed.

The second study sought additional evidence for cognitive processes promoting inclusive fitness with a modified methodology. Scenarios similar to those in the first study were used; however, the items were modified to enhance construct validity. In critical items the respondent was described as performing a beneficial action towards an individual. The respondent was asked to rate the action on three 9-point bipolar scales which read: ''How rational is this decision?,'' ''How ethical is this decision?,'' and ''To what degree would you feel obligated to choose this action?'' A degree of cost and/or risk was introduced to the actions in the scenarios to avoid ceiling effects (Kruger, In Press b).

It was predicted that kin selection would be evident on life, tangible, and intangible resource items via ratings on the rational, ethical, and obligation scales. The tendency for kin selection was not predicted to be as strong for the pleasant experience scenarios, because this form of assistance is unlikely to affect survival or reproductive success. An interaction between gender of the target and type of scenario was also hypothesized. Ratings for male relatives were expected to be higher than those for female relatives on tangible and intangible resource items. Eight different forms of the questionnaire were used to match eight targets with each of the items: brothers, sisters, nieces, nephews, male and female cousins, male friends and female friends (Kruger, In Press b). Contrast results were evaluated using the HC-Holm procedure (Toothaker, 1993), to hold ERFW at .05.

A 4 (type of scenario) x 4 (relationship distance) x 2 (gender of target) x 2 (gender of respondent) ANOVA was used to analyze the data from each scale. The ANOVA for scores on the rational scale found main effects for relation, scenario, and a significant interaction between relation and scenario. This pattern was replicated for the ethical and obligation scales. Rescue attempts were considered more rational for siblings than for the others. Providing tangible resources for a nephew or a cousin was considered more rational than for a friend. Providing tangible resources for a nibling was considered more rational than for a cousin. Providing intangible resources for a sibling was seen as more rational than for the others. Contrary to predictions, providing intangible resources to a cousin was seen as more rational than to a nibling. Only one contrast between friends and all relatives was performed on the situation scenarios, because this type of assistance is not likely to affect survival or reproductive fitness. No difference was found between the rationality of providing pleasant situations for friends and relatives (Kruger, In Press b).

Making a life saving attempt for a sibling was considered to be more ethical than an attempt to save the others. Participants rated the provision of tangible resources to niblings and cousins as more ethical than provisions to friends. Providing intangible resources to a cousin was seen as more ethical than for a nibling, which was opposite of the prediction. The most critical test of kin selection, a difference in obligation to siblings and all others, was significant for life, tangible resource, and intangible resource scenarios. Obligation to provide tangible resources for a nibling was higher than for a cousin. Obligation to provide intangible resources for friends was higher than for niblings or cousins, contrary to prediction. As predicted, there was no difference in obligation to provide pleasant situations for friends or relatives (Kruger, In Press b).

The results from this study advance the altruism literature by illuminating the psychological qualities of kin selecting processes enhancing inclusive fitness. Ten orthogonal linear contrasts indicated that participants significantly favored the closer relation when considering fitness enhancing assistance. Ratings of the rationality of providing assistance and feelings of obligation to provide assistance showed the strongest effects of kin selection. Although the self-report format of this experiment is a limitation, feelings of obligation to perform a specific action do predict actual helping (Schroeder et al., 1995). Judgments of the ethical nature of assistance were less influenced by relationship distance. The flat scores and non-significant contrasts for pleasant situation scenarios provide divergent validity. Kin selection for this form of assistance would not be adaptive because it would not impact survival or reproductive fitness.

The strongest support for kin selection was seen in the most critical test of the hypothesis, the linear contrasts between siblings and all others, as siblings share the highest proportion of genetic information. The other comparisons provided weaker support for kin selection. Cultural changes in family structure and dispersion may have rendered kinship identification cues such as physical proximity less reliable than they were in the ancestral past. Burnstein et al. (1997) found that the perceived relationship distance between siblings and moderately distant relatives was greater than the actual genetic distance.

The establishment of social norms for altruistic actions may be another factor explaining weak kin selection for moderately distant relatives. Solitary altruistic actions will occur because the donors may some day find themselves in need and could expect to benefit from help. As long as this help occurs, altruistic actions benefiting non-relatives will be performed. The higher degree of social isolation prior to modern times increased the chances that other altruists would benefit from altruistic behaviors, leading to the propagation of traits that encourage helping (Schroeder et al., 1995). These two studies indicated that one is able to illustrate the cognitive, emotional and motivational processes facilitating kin selection through the framework of traditional social psychological research. These actions may be costly to the donor and therefore considered altruistic from the perspective of individuals, however they benefit the genes promoting the actions.

Reciprocal Altruism Theory

Kin selection is not the only influence with a basis in evolution that could produce altruistic helping behaviors. The theory of reciprocal altruism predicts that altruistic behaviors will also be a function of beliefs about the recipient’s likelihood of reciprocating (Trivers, 1971). The exchange of resources and support in times of need is adaptive due to benefits conferred to the viability of the group as a whole. Solitary altruistic actions will occur because the donors may some day find themselves in need and could expect to benefit from help. As long as this occurs, altruistic actions benefiting non-relatives will occur. The development of this tendency was facilitated in the environment of evolutionary adaptation (EEA), where a higher degree of social isolation increased the chances that other altruists will benefit from others’ altruistic behavior, and the propagation of traits which encourage helping (Schroeder et al., 1995).

Reciprocal altruism and kin selection are the only mechanisms for the evolutionary maintenance of altruistic traits whose theoretical bases have received widespread acceptance (Rothstein & Pierotti, 1988). Trivers (1971) stressed that reciprocal altruism is a phenomenon distinct from kin selection. Reciprocators are likely to establish long-term relations and to deliver most of their aid to other individuals who are genetically predisposed to reciprocation. Most acts of reciprocal altruism should involve indirect increments to inclusive fitness, at least in regards to alleles for reciprocation. Reciprocal altruism must involve aid that is returned to an original donor (directly or indirectly) as a result of a behavior that has a net cost to an original recipient. Reeve (1998) suggests a third possible class of selective mechanisms for the evolution of costly helping behaviors, by-product mutualism or pseudoreciprocity. In this scenario, an individual performs a helping action at a cost to itself, but the target provides a benefit in return as an incidental by-product of its own selfish actions. Reeve (1998) notes that cooperation outside of mating is not common in the animal kingdom. These theories deal specifically with behaviors that are considered “altruistic” from the perspective of the donating individual. The existence of mutually beneficial simultaneous behaviors performed by organisms cooperating with each other is well established (Levy, 1999).

Group selection

Arguments for an evolutionarily stable strategy (ESS) of cooperation to promote the "good of the species" are usually rejected because natural selection operates more effectively within breeding populations than between them (Reeve, 1998). David Sloan Wilson and Elliot Sober have recently attempted to reanimate group selection theory (Horgan, 1996). Wilson (1997) holds that natural selection on individuals cannot explain the existence of altruistic behaviors. Altruists may be less fit than non-altruists within a single group, but groups of altruists are more fit than groups of non-altruists. Although groups may not think as a unit, they may act as a unit and shift the competition from between-individuals to between-groups. This would seem to concur with the inherent in-group/out-group cognitive biases known in social psychology, such as the ultimate attribution error. Social psychologists concur that activation of group stereotypes, which may contain an evaluative component, precedes conscious control and happens whenever the discriminating features of a group are present (Tesser & Martin, 1996).

Morell (1996) echoes this argument with the honey bee example. He states that colonies operate as individual units or super-organisms, because only the queen reproduces, and workers’ genes are passed along through her. Selection operates at the hive level, rather than that of the individual. Although this framework can be used to illustrate the value of cooperation within groups, its logic can ultimately be reduced to selection at the individual level. Because of the nature of reproduction in bees (diploid queen, haploid male drones and diploid but sterile female workers), workers maximize their own genetic fitness through cooperation. The offspring produced by the queen has an r of .75 with the other workers, which is higher than the r of .5 usually achieved in sexual reproduction. Although the specialization in tasks benefits the group, it resembles a caste system more than an egalitarian society. Even in social insect groups which have more than one queen in a hive, such as the epiponine wasp Brachygastra mellifica, workers are on average significantly more related to queens than to other workers (r of .37 versus .23) and should therefore suppress each other in order to let the queens produce the eggs. Though many workers have developed ovaries and could lay eggs, the genetic analyses showed that most or all males come from queens (Hastings, Queller, Eischen & Strassmann, 1998).

Although the existence of altruistic behaviors deriving from group-selection is a theoretical possibility, most scientists believe that few, if any species have met conditions necessary for group selection (Krebs, 1998). This would require between-group selection for altruism to occur at a faster rate than within-group selection for selfishness, and the chance of selfish individuals invading the group must be low. The newer group selection models mirror those of individual selection, so they can be mathematically translated into each other (Reeve, 1998). Assuming that the tendency to sacrifice oneself for the sake of one’s group varies among individuals within groups, those with more selfish tendencies will survive better than their more altruistic neighbors. This would lead the group to eventually become more selfish in nature. In the case of harvester ants, victory in multi-colonial between-group competitions leads to fatal competition between queens of the victorious colonies (Reeve, 1998). Because the evidence for group selection is weak at best, this type of influence will not be examined in the proposed study.